SECURITIES BORROWED, LOANED AND SUBJECT TO REPURCHASE AGREEMENTS - Repurchase Agreements by Class of Collateral (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Assets Sold under Agreements to Repurchase
Repurchase agreements	$ 477,635	$ 296,218
Securities lending agreements	29,365	33,269
Total	507,000	329,487
U.S. Treasury and federal agency securities
Assets Sold under Agreements to Repurchase
Repurchase agreements	191,944	99,979
Securities lending agreements	0	106
Total	191,944	100,085
State and municipal securities
Assets Sold under Agreements to Repurchase
Repurchase agreements	1,434	1,911
Securities lending agreements	2	0
Total	1,436	1,911
Foreign government securities
Assets Sold under Agreements to Repurchase
Repurchase agreements	161,785	123,826
Securities lending agreements	626	13
Total	162,411	123,839
Corporate bonds
Assets Sold under Agreements to Repurchase
Repurchase agreements	15,761	14,308
Securities lending agreements	23	45
Total	15,784	14,353
Equity securities
Assets Sold under Agreements to Repurchase
Repurchase agreements	15,478	9,749
Securities lending agreements	28,228	33,096
Total	43,706	42,845
Mortgage-backed securities
Assets Sold under Agreements to Repurchase
Repurchase agreements	67,390	36,225
Securities lending agreements	0	0
Total	67,390	36,225
Asset-backed securities
Assets Sold under Agreements to Repurchase
Repurchase agreements		1,755
Securities lending agreements		0
Total		1,755
Other
Assets Sold under Agreements to Repurchase
Repurchase agreements	23,843	8,465
Securities lending agreements	486	9
Total	$ 24,329	$ 8,474